Method of making polishing disks



Nov. 10, 1953 2,658,802

H. STAHEL METHOD OF MAKING POLISHING DISKS Filed July 17. 194'? INVENTOR. una/zel Patented Nov. 10, 1953 OFFICE METHOD F MAKING POLISHING DISKS Hermann Stahel, Zurich, `Switzerland Application July 17, 1947, Serial No. 761,543 `In Switzerland November 2, 1945 Section 1, Public Law 690, August 8, 1946 Patent expires November 2, 1965 z claims. (c1. soo-21) I The present invention relates tota polishing disk formed of threads mounted on` a hub and which, among other things, is intended for use in the watch industry, in goldsmiths shops, etc., particularly for polishing precious metals.

According to the invention the polishing disk includes a two-part hub which receives threads held fast thereon by a ring member.

A particularly convenient mode of producing the polishing disk consists in that a thread bundle loosely held together by a ring is axially protruded bya tapered mandrel whose thick end snugly ts Vand lies flush with the one hub-part until said bundle rides on the latter, the thread portions still lying on the mandrel being thrown radially outwardly to expose the inner edge of the hub part, whereupon the mandrel is withdrawn and its place taken by the other hub part, to form the composite hub.

In preparing the desired thread bundles each -held together by a ring, any length of a group of threads may preferably be passed through a funnel-fashioned tubular guide, from which the holding rings are shifted thereonto at even intervals readable on a graduation scale allocated to said guide, whereupon the group of threads set by evenly spaced rings is each time cut off in the middle between two ring members to obtain sections of uniform length.

The accompanying drawing illustrates by Way of example a preferred form of embodiment of the invention, together with the means to execute it.

Fig. 1 is a top View of the appliance for setting the mounting rings at desired intervals on any length of bundled threads,

Fig. 2 is a lateral view of the appliance, partly in longitudinal section, with the thread bundle inserted and the ring members arranged thereon,

Fig. 3 shows a thread bundle cut to useful size,

Fig. 4 shows a mounting ring, in side elevation,

Fig. 5 is a cross section thereof,

Fig. 6 is an exploded view illustrating the two hub parts of the polishing disk,

Fig. '7 shows a mandrel as the means for preparing the disk,

Fig. 8 illustrates the protruding mandrel with one hub part fitted to its thick end, said hub part forming the seating for the thread bundle,

Fig. 9 shows the mandrel as entirely passed through the thread bundle,

Fig. 10 is an exploded View illustrating the part of the hub carrying the thread bundle, the

. neck-strengthening part I2.

safety` part thereof being ready to be fitted thereto,

Fig. 1l is the finished polishing disk, partly in cross-section.

The polishing disk as illustrated comprises a `flanged hub formed of two parts I, 2 which may, forrinstance, be of wood. Hub part I forms the seating for the thread bundle 3, and hub part 2 serves as retaining `or safety member. Hub part I has a flange 4l, an axial cylindrie bore 5 and an axial tapered bore 6. Hub part 2 possesses a flange 'l and a cylindric portion fitting into bore 5, said portion being provided with a tapered bore 6. `A metal ring 8 serves to hold the threads 3 on the hub.

For preparing the polishing disk a tapered mandrel 9 is utilized as an auxiliary tool having on its thick end a reduced cylindric extension I0 adapted in diameter to bore E and onto which hub part I can be put.

The appliance as shown in Figs. 1 and 2 serves to prepare the thread bundle 3 to be mounted on the hub, and same including a tubular guide II having at one end an insertion funnel I3 with a The diameter of the tubular guide I I is so dimesionedl that the ring members 8 to be brought onto the bundle can be loosely located thereon, as shown in Fig. 2. Attached to the neck-strengthening part I2 is a graduation scale I4 so arranged as to not impede the easy location of the rings 8 on guide II. The g-raduation scale I4 extends beyond the tubular guide, the divisions beginning exactly at its rear end.

Any length of threads intended for preparing the bundle may, as shown in Fig. 2, be passed through the funnel I3 into the tubular guide II adapted to take a sufficient number of mounting rings 8. The thread bundle having been passed through said guide so f-ar that a portion corresponding to a half-length of a required section projects out of the guide-what is exactly readable on the graduation scale-the nearest ring 8 is pushed thereon so as to still abut on the end of said guide, until the bundle is drawn farther a desired length with the rst ring, whereupon another member is shifted onto the threads which again shall abut on the end of said guide. 4From now on the bundle is repeatedly drawn farther a required amount and -a ring member pushed each time thereon under zero of the scale until the whole bundle is set with rings in evenly spaced relationship. Subsequently the bundle is each time out between two rings to obtain equal sections.

Now, mandrel 9 with hub part I fitted lto its thick end is pushed endwise into such thread bundle until this rides denitely on said part l, whose flange 4 causes one half of the threads to stand up, the other half still lying on mandrel 9 being thrown 'radially outwardly to expose the hub part. Upon withdrawal of mandrel 9 the hub part 2 is glued and pressed onto part I, whereby the ends of the threads 3 extend and are maintained radially outwards 4'clue 'to the flanges of the assembled hub. The outer edges of the radially extending threads are peripherically equalized by a cylindric punching knife con centrically applied to the hub to ensure in practice a true circle of the polishing disk. `When the glue is dry the polishing disk is 'ready 'orl'se. I

For a thread bundle the most varied materials may be utilized, such as woollen, ber 'or metal threads, etc. In a modification several rings or thread bundles may be arranged side by side on Ia oinmon fhub. It is also possible to make the polishing rdisk mechanically.

What I claim Sis:

1. A method for preparing a polishing disc having fa twohpiecelanged hub consisting in "takin'g "a Vbundle el longitudinally extended threads, applying a ring-like member 'about Tthe bundle of threads approximately 'meol-ially or the ends thereof, inserting a tapered mandrel through 'the having a two-piece flanged hub consisting in guiding fa plurality of threads along a predetermined path, applying ring members about the `threads 'in suitably spaced relation, cutting the center fof "the lbundle of threads `on the vring irleln` |30 1ber, removably arranging *a 'hanged hub 'part -on the enlarged end of the mandrel and allowing the same to remain thereon until the threads and 'ring member ride on the said hub part with 'the threads abutting the flange of the hub part,

threads at points between the ring members to .provide bundles of threads, inserting a tapered .mandrel with one hub part removably mounted on the enlarged end thereof through the threads on a ring member until the threads and ring member ride on the hub part, throwing the threads remaining on the mandrel radially outwardly, withdrawing the mandrel and applying the other hub part lto the rst hub part in place 'of -th'e mandrel 'to form la vcomposite hub with the ilang'es of 'the parts 'clamping land holding the radially extending threads in position.

References v"Cited in lthe le of this patent UNITED STATES PATENTS 

